Fluid seal



Feb. 7, 1939. L, A. JQHNSON 2,146,677

FLUID SEAL Filed Aug. 5, 1936 INVENTOR.

ATTORNEY Patented Feb. 7, 1939 UNITED STATES FLUID SEAL Lloyd A. Johnson, Hillsborough, Calif., assignor to National Oil Seal Co., Oakland, Calif., a. corporation of Nevada Application August 5, 1936, Serial No. 94,326

1 Claim.

My invention relates to improvements in 'fluid has been found that felt, because of its wick-likev action, draws oil and is unsatisfactory.

Sealing units using leather for the sealing member, though at present widely used, have been found unsatisfactory in many respects. For instance, in the matter of securingthe sealing member in the cage in a leak-tight, non-rotative .0 fit. Also, leather is susceptible to the action of oil and gradually becomes softened and saturated with oil. In those using spring means to hold the leather sealing lip in contact with an axle, as

the leather becomes softer and more pliable a 35 greater sealing surface is brought into contact with the moving p-art, resulting in greater frictional resistance and rapid wearing out of the leather sealing edge, as well as scoring of the shaft. Leather is not uniform in texture, there- 30 fore it is necessary to have a greater sealing edge in contact with va movable shaft to insure a positive seal. This, too, results in greater frictional resistance which is a serious problem in sealing low powered units. Finally, the lack of uniformity of leather presents serious manufacturing problems in quantity production. Composition fluid seals made wholly of rubber or compositions with similar characteristics, in which reenforcing means are embedded, near o the outer rim. possess many disadvantages. In use it has been found that the'units expand as a result of frictional heat, this expansion urging more of the sealing lip onto the movable shaft, thereby developing greater frictional resistance.

4" This in turn develops more heat, resulting in still greater expansion, until the unit as a whole becomes compressed beyond the elastic limit of the material. Upon cooling it shrinks away from the m housing, destroying the peripheral oil-tight fit at that point and allowing oil to leak out. Cold flow is also a problem with this type of seal.

These and other defects'found in the conventional type of fluid seals present a difficult prob- 55 lem in the newer and faster automobiles and other machinery having parts which now operate with so much higher shaft speeds.

It is therefore an object of my invention to combine the good features of the metal encased seal and of the composition seal, to provide a fluid seal having a metal or rigid heel portion and a sealing lip made of composition material in which the bearing area of the sealing lip on the movable part is small, resulting in low frictional resistance and cool operation.

Another object is to provide a fluid seal in which the parts are bonded together making leak-proof joints between the sealing member and its heel portion.

Another object is to provide a fluid seal having a composition sealing edge which will not develop greater frictional resistance as the unit becomes worn or heated, due to the control effected by the heel portion.

Another object is to provide a fluid seal which is free to expand as a result of frictional heat without exerting substantial additional pressure on the sealing lip. l

Another object is to provide a fluid seal having a self-sustained press fit allowing a smaller over-size diameter clue to its greater strength.

Other objects and advantages will be apparent from the following description and claim.

In the drawing forming a part of this specification: i

Fig. 1 is a perspective view of a sealing unit with a section removed to show the arrangement of the component parts;

Fig. 2 is a modified form;

Fig. 3 is a modified form adapted to be bolted on to a housing;

Figs. 4 and 5 are further modifications; and

Fig. 6 shows an external form of seal.

In Fig. 1 is shown a seal comprising broadly a composition sealing portion 1, outer metal cup or heel 8, inner cup I0 and garter spring I I.A The composition body portion 'l includes radial portion I2 having outer surface I8 and axial portion I4 terminating in sealing lip I5, and spring retaining groove I6.

The outer cup or heel 8 consists of radial wall I'l having p-erforations I3, radius 20, peripheral sealing face 2|, radius 22, and spun over portion 23. It may be of metal or other hard substance.

The inner cup l0, which may be of metal or composition, consists of circumferential wall 24, inset radial wall 25, radius 26, and radial wall 21.

'I'he composition body portion 'l is formed in a mold, and it is preferable to use an oil resisting composition, such as Duprene. The comof cement which will insure a good bond between the composition and the metal. Next the composition is placed in the mold and the mold lil closed. Under pressure the composition material will flow into openings I3 of wall I1 and tie/or bond the parts together. The mold is also shaped to form spring receiving groove I6. As the composition cools it shrinks approximately one per cent which further tends to make the composition material embrace the metal.

When cooled, it is removed from the mold and garter spring II placed in groove I6. The inner cage I is placed within outer cage 8 and flange 23 of outer cage 8 is spun over against inset radial wall 25 of the inner cage, firmly holding the parts together. Radial portion 21 retains garter spring II in position and protects the composition sealing lip from injury by movable parts. Radial ridge 20 projects outwardly beyond the side I3 of the composition part of the seal and provides a protecting edge for the wall I3.

In Fig. 2 a modified form of construction is shown in which the rubber composition material is bonded to spacing washer 35. In manufacturing this type, the spacing washer 35, which may be of metal or composition material is positioned in the mold with the composition. The composition will adhere to the side of washer 35 and also flow into holes 36 to strengthen the bond between the parts. The outer cage 30 consists of radial wall 3l, having a series of indentations 32, circumferential portion 33 and spun over lip 34. Inner cage 31 consists of radial wall 38, offset 40, and circumferential portion 4I.

In assembling this unit, the composition radial portion I2 and spacing washer 35, which are bonded together, are placed within outer cage 36 and garter spring II is placed in groove I6. Inner cage 31 is then placed within outer cage 30 and portion 34 is spun over, securing the parts 'together firmly. Circumferential portion 4I of the inner cage abuts against spacing washer 35, pressing it and the radial portion of the composition material rmly against the bottom of cage 30. The inwardly disposed indentations 32, preferably non-perforate, located in wall 3|, embed themselves in the composition material and serve to anchor it against rotation. Washer 35 with its bonded sealing member is capable of being used alone in this form in a housing by pressfitting 'the washer therein, or by means of a gland.

In Fig. 3 is shown a'sealing unit adapted to be bolted on the end of a housing instead of being press-fitted within the housing. The parts of this seal are the same as shown in Fig. 1 with external metal member 43 added, which ts over outer cage 8 of the seal. External member 43 includes turned over ridge 44, circumferential portion 45, downwardly disposed dinks 46 and radial wall 41 in which are bolt holes 48. The seal unit of Fig. 1 is press-tted into external metal member 43, forming an oil-tight t between circumferential part -45 of the external member and circumferential part 2I of the seals outer cage. Downwardly disposed dinks 46 extend a short distance down over spun over portion 23 of the seals outer cage 8, to hold it in place. Radial wall 41 is adapted to be bolted on position can be Varied to suit the material being the end of a housing and form the end wall of said housing. Y

Fig. 4 shows another modified form of seal similar to the type described in Fig. 2, except that the composition radial portion I2 is bonded to the inner side of radial wall 3l of the outer cage. 30. A series of holes 50 are located in this wall 3I of the outer cage and aid in securing a good bond. Washer 84 is put inplace against composition sealing member I2. II is placed in groove I6. Inner cage 31 is then placed within outer cage 30 and portion 34 of the outer cage is spun over, holding the parts firmly together. circumferential portion 4I of the inner cage presses against washer 84, pressing it rmly against the radial portion I2 of the composition material.

Fig. shows another modifled form of seal consisting of metal cage or heel 5I, composition part 52, and garter spring II. The metal cage 5I includes radial portion 53, with holes 54, radial ridge 55, peripheral portion 56, and small inwardly extending radial portion 51. In this type the composition material will flow on both sides of radal portion 53 into holes 54. It will adhere to the sides of radial portion 53 and the composition which has flowed through holes 54 further strengthens the bond between the composition material and metal. Radial ridge 55 extends yout slightly beyond the plane of side I3 of the composition material and provides a protecting shoulder. Small inner radial portion 51 extends out beyond the plane of the composition sealing lip I5, forming a thrust surface protecting the sealing material from 4moving parts within a housing. While I mention heel 5I as made from metal, it may in some cases be made from compsition of a fair degree of hardness.

Fig. 6 shows a seal similar to Fig. 1 in which the parts are reversed forming a unit in which the composition sealing lip is on the outer periphery and the metal parts adapted for pressfitting on a shaft.

In the drawing (Fig. 6) the unit is shown comprising composition sealing` portion 60, outer metal cup 6I inner metal cup 62 and an expanding type garter spring I I. The composition member consists of radial portion 63, body portion 64, sealing lip 65 and spring groove 66. The outer cage consists of radial part 61, having openings 68, radial ridge 1U, axial portion 1I, having inner periphery 12 and spun over part 13. Inner cage 62 consists of circumferential part 14, inset radial part 15, offset 16, and thrust' surface 11. The composition material will adhere to both sides of radial Wall 61 and flow through holes 68, forming a secure bond between the composition and metal as explained previously. Garter spring II fits groove 66. Inner cage 62 is placed within outer cage 6I and portion 13 is spun over. Radial ridge of the axial metal cage 6I extends outwardly beyond the plane of radial wall 63 of the composition material and forms a protecting shoulder for the composition material. Radial Wall 11 secures garter spring Il against removal and provides a thrust surface protecting the seal from moving parts within a housing.

The external type of seal shown in Fig. 6 is press-fltted onto a shaft and the inside surface 12 of the axial portion 1I of the metal cage makes an oil tight joint between the axle and cage. Garter spring II urges the composition sealing portion outwardly, pressing the sealing lip 65 against the inner Wall of the housing to form an oil tight seal. The, composition sealing Garter spring portion is free to compress inwardly against the action of garter spring il as the result of any expansion due to heat being generated.

By using ,an oil resisting rubber composition material, such as Duprene", which is consistent in texture, only a short shaft contacting surface is required to provide an effective seal. Duprene is unaffected by oil and does not become soft and abby after being soaked in oil, consequently the garter spring cannot pull the long axial portion of the sealing edge onto the shaftand thereby develop greater frictionairesistance. The heel portion also functions to control the sealing lip. Since the frictional resistance is low due to the short shaft contacting surface, any expansion due to heat generated by friction is slight.

While I have illustrated and described some forms of my invention. it is obvious that the design may be varied and still be within the spirit of the invention as defined in the appended claim. l

What I claim is:

An oil seal of the type adapted for insertion to seal the annular space between the shaft and a bore in a housing, comprising a cup member having a peripheral portion and an axially inwardly onset radial ange. a molded resilient sealing member bonded to both sides of said radial ange at said offset so that its outer radial face lies within the radial plane of the cup bottom where it bends inward to form said offset, whereby said molded material is protected from wear by contact with adjacent moving parts.

LLOYD A. J OI-INBON, 

